Alterations of the CCND1 and HER-2/neu (ERBB2) proteins in esophageal and gastric cancers

We evaluated the relationship of amplification and polysomy of both the CCND1 and the ERBB2 (alias HER-2/NEU) genes to the overexpression of their proteins in esophageal and gastric cancers and also their association with clinicopathological features. CCND1 gene amplification (45%) was more prevalent than polysomy (25%) in esophageal carcinoma, but the pattern observed was similar in gastric adenocarcinoma (10% amplification, 15% polysomy). For ERBB2, polysomy was a more frequent mechanism than amplification in both esophageal (32.5 vs. 7.5%) and gastric (15 vs. 5%) cancers. Overexpression of cyclin D1 protein was identified in 37.5% of the specimens of esophageal tumors and 35% of gastric tumors, and overexpression of Her-2/neu protein in 12.5 and 7.5%, respectively. The K-statistics revealed a fair agreement in both types of turners only in overexpression and amplification of the CCND1 ggene; the ERBB2 gene showed a fair agreement in amplification and polysomy and the level of protein expression in gastric adenocarcinorna. Thus, polysomy 17 could contribute to a high Her-2/neu protein level, at least in gastric cancer. Our data indicated an association with alcohol consumption and the CCND1 gene or protein levels, in both esophageal and gastric cancers. (c) 2006 Elsevier B.V. All rights reserved.

Chromosome breakpoint distribution in nonmelanoma skin cancers

We have identified chromosome regions that may be sites of genes activated as a result of chromosomal rearrangements observed in 61 of the 86 skin tumors referenced in the literature. The data showed that most of the breakpoints were distributed throughout the genome and some tended to cluster. Highest frequencies of breakpoints were observed in chromosomes with high relative length, except chromosomes 14 and 15 that were more often affected in malignant tumors, despite their size. Our work provides a starting point for more detailed studies that may allow identification of these genes as important keys in the development and progression of skin cancers. (C) Elsevier B.V., 1997.

Possible implication of Mdm2 as a prognostic marker in invasive laryngeal carcinoma

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Clinicopathological analysis of head and neck chondrosarcoma: three case reports and literature review

Chondrosarcoma (CHS) is a malignant neoplasm characterized by the formation of cartilaginous matrix by neoplastic cells, with a high propensity for local recurrences. Head and neck CHS is rare, accounting for less than 12% of all cases of CHS, usually affecting the maxilla. The majority of affected patients are in the fourth decade of life, with a slight predilection for male patients. A painless swelling is commonly the most frequent complaint. Surgery with wide en-bloc resection is the preferred treatment for CHS; radiotherapy and chemotherapy are usually palliative options. Owing to its rarity, there are few clinical series evaluating the biological behaviour of head and neck CHS. The aim of this study is to analyse the clinicopathological characteristics of head and neck CHS by reporting 3 new cases of this neoplasia affecting the jaw bones and reviewing the clinical series previously published in the English literature.

Analysis of the TAX1BP1 gene in head and neck cancer patients

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Distinct regions of loss of heterozygosity on 22q at different sites of head and neck squamous cell carcinomas

Background: Frequent loss of heterozygosity (LOH) has been reported in many types of cancer, including head and neck carcinomas. Somatic deletions involving specific chromosomal regions are strongly associated with inactivation of the allele of a tumor suppressor gene located within the deleted region. In most studies concerning LOH in head and neck squamous cell carcinomas (HNSCC) the different anatomical sites are not distinguished. The behavior of tumors arising at various sites differs significantly, however, suggesting different intrinsic tumor properties. In this study we compared the LOH on 22q and its relationship to clinicopathological parameters at the three major sites of HNSCC: oral cavity, larynx and pharynx. Material/Methods: LOH and microsatellite instability (MSI) were studied using seven polymorphic microsatellite markers mapped to the 22q11-q13.3 region in 37 oral, 32 laryngeal, and 31 pharyngeal carcinomas. Results: Two separate regions of LOH were identified in the laryngeal (22q11.2-12.1) and oral cavity (22q13.1-13.31) tumors. When the different anatomical sites were compared, a statistically significant difference was found between the presence of LOH at D22S421 (p<0.001), D22S315 (p=0.014) and D22S929 (p=0.026) in the laryngeal tumors. Conclusions: These data suggest that distinct regions on 22q are involved in LOH in oral cavity and laryngeal tumorigenesis but do not support a similar association between the development of pharyngeal tumors and genes located on 22q. These findings implicate the presence of different tumor suppressor genes mapping to distinct regions on chromosome 22q in oral and laryngeal carcinomas.

Influence of preventive dental treatment on mutans streptococci counts in patients undergoing head and neck radiotherapy

The aim of this study was to evaluate the influence of chlorhexidine gluconate, sodium fluoride and sodium iodine on mutans streptococci counts in saliva of irradiated patients. Forty-five patients were separated into three experimental groups and received chlorhexidine (0.12%), sodium fluoride (0.5%) or sodium iodine (2%), which were used daily during radiotherapy and for 6 months after the conclusion of the treatment. In addition, a fourth group, composed by 15 additional oncologic patients, who did not receive the mouthwash or initial dental treatment, constituted the control group. Clinical evaluations were performed in the first visit to dental clinic, after initial dental treatment, immediately before radiotherapy, after radiotherapy and 30, 60, 90 days and 6 months after the conclusion of radiotherapy. After clinical examinations, samples of saliva were inoculated on SB20 selective agar and incubated under anaerobiosis, at 37oC for 48 h. Total mutans streptococci counts were also evaluated by using real-time PCR, through TaqMan system, with specific primers and probes for S. mutans and S. sobrinus. All preventive protocols were able to reduce significantly mutans streptococci counts, but chlorhexidine gluconate was the most effective, and induced a significant amelioration of radiotherapy side effects, such as mucositis and candidosis. These results highlights the importance of the initial dental treatment for patients who will be subjected to radiotherapy for head and neck cancer treatment.

Head and neck carcinogenesis: Impact of MTHFD1 G1958A polymorphism

Objective: To investigate the MTHFD1 G1958A polymorphism involved in the folate metabolism as a risk for head and neck cancer, and to find the association of the polymorphism with the risk factors and clinical and histopathological characteristics. Methods: Retrospective study investigating MTHFD1 G1958A polymorphism in 694 subjects (240 patients in the Case Group and 454 in the Control Group) by Restriction Fragment Length Polymorphism (RFLP) Analysis. Multiple logistic regression and chi-square tests were used in the statistical analysis. Results: Multivariable analysis showed that smoking and age over 42 years were disease predictors (p < 0.05). MTHFD1 1958GA or AA genotypes were associated with smoking (p = 0.04) and alcoholism (p = 0.03) and were more ofen found in more advanced stage tumors (p = 0.04) and in patients with a shorter survival (p = 0.03). Conclusion: Te presence of MTHFD1 G1948A polymorphism associated with smoking and alcoholism raises the head and neck cancer risk.

Pesquisa de segunda neoplasia em boca e orofaringe em pacientes portadores de carcinoma espinocelular (CEC) de esôfago, boca e orofaringe através de narrow band imaging (NBI)

Pós-graduação em Pesquisa e Desenvolvimento (Biotecnologia Médica) - FMB

Avaliação da qualidade de vida relacionada ao impacto da terapia com iodo-131 em pacientes com câncer bem diferenciado de tireóide (CDT) na infância

Pós-graduação em Pesquisa e Desenvolvimento (Biotecnologia Médica) - FMB